The mans alive and kicking, the price would be 0$ until he actually dies. 25-30 years you will profit. LOL
Here's an analogy to help you with your estimate: how much would you pay for RIPMichaelJackson.com 20 years ago? (had Internet been alive and kicking at the time )
you got some work to do, before that domain is worth anything but seriously now, if you can hold on to it it will be ok in a few years, but for now....